This invention relates to an acoustic transmission line loudspeaker.
Many conventional loudspeakers utilize waveguides to guide sound pressure waves along a convoluted path within their enclosures. Depending on the characteristics of a given waveguide, a certain portion of the energy present in the sound pressure waves is absorbed while traveling through the waveguide and another portion of the energy passes through the waveguide and is radiated as sound into an external environment. It is often the case that the waveguide is configured such that sound radiated from the waveguide enhances the low frequency output of the loudspeaker.
Some complex conventional loudspeakers include a number of volumes, at least some of which are connected by ports and/or passive radiators. Such loudspeakers include an acoustic transducer which radiates directly into one or two of the volumes. The sound radiated from the transducer propagates through the volumes, through the ports and/or passive radiators, and is eventually radiated into an external environment. The number and size of volumes along with the number, size, and placement of the ports and/or passive radiators are chosen to achieve a desired characteristic in the sound radiated into the external environment.